37,389 research outputs found

    Uses of volcanic ash beds in geomorphology

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    In geomorphology air-fall volcanic ashes possess high value as marker beds. These have proved particularly useful in studies associated with infilling of flood plains, fan building, terrace correlation and chronology, erosion, shoreline and sea level changes, recent tectonics, archaeology and ground surfaces. Ash beds and the community are also discussed

    An Introduction to the Battle for the Melfa River

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    The battle for the Melfa River on 24 May 1944 started with Lieutenant-Colonel Vokes’ VOKESFORCE, based on the British Columbia Dragoons, advancing through the breakthrough of the Hitler Line at about 0800 hours. This force established a firm base, codeword KUMMEL, about 2,000 yards beyond the 3rd Infantry Brigade salient. STRATHFORCE, (also known as #8220;Griffin Force,#8221;) based on Lieutenant-Colonel Griffin#8217;s Lord Strathcona#8217;s Horse (RC), moved through KUMMEL at about 1330 hours. Its objective was to seize a crossing of the Melfa River

    Volcanic ash beds in the Waikato district

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    This report lies somewhere between the "pathfinder" variety and the completed account for the reason that the results of detailed mapping and identification are still being prepared for publication. For the younger beds less than 36,000 years we now know both the source and the distribution, but for the older ashes commonly referred to as the Hamilton ash, sources are unknown and a knowledge of distribution restricted to the Waikato district. The principal source is the Okataina volcanic centre with Taupo as a subsidiary (Healy, 1964; Thompson, 1964 :44), and on this information, current mapping into the Waikato district proceeds from the east. Under the circumstances of partly completed work it seems prudent to discuss relevant ash beds already known (Vucetich and Pullar, 1963:65-6; 1964:45-6) to introduce briefly current work by the same authors and by W. T. Ward, and then to relate all of this to previous work portrayed in a soil-forming ash shower map by Taylor (1953)

    The kinetics of calcite precipation and related processes

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    This review is concerned with the kinetics of calcium carbonate formation and related processes which are important in many hard waters

    A description of n-ary semigroups polynomial-derived from integral domains

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    We provide a complete classification of the n-ary semigroup structures defined by polynomial functions over infinite commutative integral domains with identity, thus generalizing G{\l}azek and Gleichgewicht's classification of the corresponding ternary semigroups

    Architecture, design, and modeling of the OPSnet asynchronous optical packet switching node

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    An all-optical packet-switched network supporting multiple services represents a long-term goal for network operators and service providers alike. The EPSRC-funded OPSnet project partnership addresses this issue from device through to network architecture perspectives with the key objective of the design, development, and demonstration of a fully operational asynchronous optical packet switch (OPS) suitable for 100 Gb/s dense-wavelength-division multiplexing (DWDM) operation. The OPS is built around a novel buffer and control architecture that has been shown to be highly flexible and to offer the promise of fair and consistent packet delivery at high load conditions with full support for quality of service (QoS) based on differentiated services over generalized multiprotocol label switching

    Regression trend lines of ridges and swales on the emergent beach at Gisborne, New Zealand

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    The emergent sand-beach system at Gisborne consists of six recognisable groups of ridges and swales. It is about three miles wide and four miles long and rises gradually from 15ft above sea level at the coast to 40ft inland. From time to time the emergent beach has been mantled with air-borne volcanic ash including ash beds of the Waimihia Lapilli, Taupo Sub-group Members 9 - 13, Taupo Pumice, and Kaharoa Ash Formations. As the dates of these eruptions are known, the times of formation of the groups of beach ridges and wales have been determined as follows: Group 1: c. 9000 B.C. - c. 1400 B.C. Group 2: c. 1400 B.C. - (?) 850 B.C. Group 3: (?) 850 B.C. - c. A.D. 131 Group 4: c. A.D. 131 - c. A.D. 1020 Group 5: c. A.D. 1020 - c. A.D. 1650 Group 6: c. A.D. 1650 - A.D. 1956 Evidence of recent earth movements has been noted in ridges and swales of Group 1, and of possible movements in those of Group 3. Changes in sea level could not be established and were taken from Wellman and Schofield. No attempt was made to distinguish directly wind-blown sand from wave-deposited sand; instead, a shell layer (assumed to be associated with the intertidal strand) was used as a marker bed to indicate the approximate sea level at the time when the shells were deposited. Elevations of ridges and swales in each group were measured on a 15,000ft transect across the beach system. Then, overall linear and quadratic regressions as well as linear regressions for each group separately were computed. For both of the overall linear and quadratic regressions the trend lines show a fall seaward, but the separate trend lines for each group are as follows: Group 1: Highly significant seaward decline. Groups 2 and 3 combined: Very highly significant seaward decline. Group 4: Highly significant seaward incline. Groups 5 and 6 combined: No significant change. The departure of the regression trend lines within Groups 1 to 6 from the overall linear and quadratic trend lines suggests that the trends of elevation across the emergent beach at Gisborne should be regarded more as a series of discontinuous trends rather than as one overall continuous trend of seaward decline. Though the overall trend of declining elevation is seaward, the corresponding fall in sea level is likely to be more apparent than real because of compounding of fall in sea level with earth movements

    IPRs, Technological Development, and Economic Development

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    In the year 2000 some $142 billion in royalties were paid internationally by users of a specific piece of knowledge that were protected under Intellectual Property Right law (IPR) to those parties that owned these rights. Under current circumstances where knowledge & innovation play an increasingly significant role in the economy (Foray & Lundvall 1996, Cowan, David and Foray 2000, Cooke 2002, Dolfsma & Soete 2006, Dolfsma 2005). IPRs have become increasingly prominent in debates and are almost unanimously deemed to favor economic development by policymakers, and certainly by policymakers in developed countries. While it has been acknowledged that some parties may benefit more from a system of IPRs than others, in relative terms a Pareto improvement is the expected outcome (Langford 1997). This has not always been the case. In addition, the academic (economic) community is almost unanimous about the system of IPR overshooting its goals. This has been the motivation to include IPRs in the WTO negotiations. The TRIPS agreement (Trade-Related Aspects of Intellectual Property Rights) has resulted in 1994 from these negotiations. Especially during the 1990s the number of patents granted has grown tremendously despite the fact that many a scholar still supports Machlup’s (1958, p.28) conclusion that:“it would be irresponsible, on the basis of our present knowledge of its consequences, to recommend instituting one. But since we have had a patent system for a long time, it would be irresponsible, on the basis of our present knowledge, to recommend abolishing it.â€From other corners, where specific effects of IPRs are considered, a different and less circumspect sound may be heard. Examples of this are attempts to make available HIV/AIDS drugs at a reduced price compared to what the pharmaceutical companies that have the patents on these drugs demand. I will focus on patents.Empirical and theoretical findings bearing on the question of IPRs’ effect on technological development, and thus prospect for economic development, are reviewed. Static and dynamic effects are distinguished. Areas where static effects may be expected include transfer of knowledge, balance of payment effects, effects for large as opposed to small firms, and effect on the ‘extent of the market’. Areas for dynamic effects include technological development and technological preemption. The list may not be exhaustive, and effects are interlocking: they may be mutually reinforcing or they may conflict. I will mostly focus on ‘dynamic’ effects.Economic Dynamics;IPRs;Intellectual Property Rights;Technological Development

    A multi-exit recirculating optical packet buffer

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    We propose a new type of recirculating buffer, the multiexit buffer (MEB), for use in asynchronous optical packet switches with statistical multiplexing, operating at speeds of 40-100 Gb/s. We demonstrate that the use of this type of buffer dramatically reduces the packet loss for a given buffer depth, thus reducing the buffer depth requirements and the overall cost of the optical packet switching. Physical layer simulation results show that it is possible to build this type of buffer with currently available active components. A hybrid optoelectronic control system is proposed, which allows control of the MEB with a minimum number of active components
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